In Barney's letter to the guys, he mentions being on vacation with Virgil--his awkward, clumsy cousin who appeared in the Season 2 episode "Cousin Virgil".
This episodes features the return of Floyd the Barber in a brief scene. Actor Howard Mcnear suffered a stroke during the third season which left him partially paralyzed. Floyd is visibly different in this episode, quieter and far less mobile. Despite Mcnear's limited mobility and failing health, he would play Floyd for three more seasons, finally bowing out before the eighth and final season. Howard Mcnear would pass away less than two years after leaving the show.